Scientific Forecaster Discussion
fxus61 krlx 191431
Area forecast discussion
National Weather Service Charleston WV
1031 am EDT Tue Sep 19 2017
weak high pressure through most of this week, with warm
afternoons and cool nights. Weak upper level impulse today into
Wednesday, with showers possible.
Near term /through tonight/...
as of 1030 am Tuesday...
Forecast on track, as the fog is nearly gone, and showers
associated with a weak upper level short wave trough, slowly
approach the western flank of the forecast area.
As of 615 am Tuesday...
Did a quick update on the clouds, as the broken/overcast deck is
arriving a couple hours earlier than previous forecast.
As of 130 am Tuesday...
Generally quiet weather continues with weak high pressure at the
surface. We do have an upper level shortwave trough and very
weak cold front approaching from the west. This is already
pushing some mid to high clouds in from the west. The cold front
looks to wash out as it reaches cwa, but with some moisture
pooled along it and the help of the upper level forcing, have
isolated to scattered showers and storms in the middle Ohio
River valley today.
Models are showing potential for showers tonight as well as the
axis of the upper shortwave trough drifts through. This feature
currently has showers and storms with it across Illinois/in, however
concerned the washed out cold front will no longer have the umph
to keep things going after the sun set. Still...maintained some
isolated showers overnight for now...at least until higher res
models add their input.
Short term /Wednesday through Thursday night/...
as of 315 am Tuesday...
An upper level wave will cross the area Wednesday bringing
chances for showers or thunderstorms. A cold front will stall or
dissipate just northwest of the area. Diurnal heating and
unstable conditions aloft will allow thunderstorms to develop
at least over elevated terrain. Drier conditions expected
Thursday and Thursday night under high pressure.
Long term /Friday through Monday/...
as of 315 am Tuesday...
High pressure will be in control of the weather conditions in
the extended forecast. Expect weak flow, mostly clear skies, and
foggy mornings. Afternoon convection on elevated heat sources
will also be possible.
Aviation /15z Tuesday through Saturday/...
as of 615 am Tuesday...
Any lingering fog will dissipate 13z-14z with VFR expected
today. Expecting some isolated to scattered showers across Ohio
River valley but not enough confidence to include even a vcsh
mention at this time. A bit more uncertain on fog potential
tonight due to clouds and showers in the area. Used a blend of
the hi-res NAM and lamp for visibility tonight...giving dense
fog across the north where fewer clouds are expected.
Forecast confidence and alternate scenarios through 12z Wednesday...
Forecast confidence: medium.
Alternate scenarios: may need to add a shower mention along and
west of I-77.Timing and density of fog may vary.
Experimental table of flight category objectively shows consistency
of weather forecast office forecast to available model information:
h = high: taf consistent with all models or all but one model.
M = medium: taf has varying level of consistency with models.
L = low: taf inconsistent with all models or all but one model.
UTC 1hrly 12 13 14 15 16 17 18 19 20 21 22 23
EDT 1hrly 08 09 10 11 12 13 14 15 16 17 18 19
crw consistency l l M h h h h h h h h M
heights consistency l M h h h h h h h h h M
bkw consistency h h h h h h h h h h h M
ekn consistency l l M h h h h h h h h M
pkb consistency M M l l h h h h h h h M
ckb consistency l l M h h h h h h h h M
After 12z Wednesday...
IFR in valley fog possible each morning this week.